Many surgical procedures depend on accurate drilling or resection of portions of a patient's bone. For example, in various spinal surgeries, a surgeon may be required to drill one or more holes in a patient's spine. However, if the surgeon drills a hole improperly, e.g., too deeply, at an incorrect trajectory or angle, etc., the surgeon may cause irreparable damage to the patient. For instance, a surgeon may be required to drill one or more pilot holes for pedicle screws to be inserted in the patient's spine. If the surgeon drills the pilot holes incorrectly, the surgeon may cause damage to the spinal cord, thereby injuring the patient.
In some surgeries, a surgeon may use a computer-assisted surgery system when drilling or resecting portions of the patient's bone. Moreover, the computer-assisted surgery system may include a haptic feedback system to constrain or inhibit the surgeon from manually moving the surgical tool beyond predefined virtual boundaries defined by haptic objects. The virtual boundaries may be established to prevent the surgeon from undesired interactions with a patient's anatomy. For example, the haptic boundaries may help to prevent the surgeon from improperly drilling or resecting the patient's bone.
However, a variety of factors such as inaccurately or improperly defined haptic boundaries, improper registration of the patient's bone to the computer-assisted surgery system, etc., may affect the accuracy of the computer-assisted surgery system. In some surgeries, such as various spinal surgeries, inaccuracies may lead to undesired interaction with the spinal cord or other nerves and injure the patient. Moreover, in some instances, such interaction may have disastrous consequences, such as full or partial paralysis, nerve damage, etc.
Patient monitoring systems are known that may be used to monitor electromyographic (EMG) activity of a patient to determine the proximity of a cutting tool or other instrument to a patient's nerve. For example, an electrical potential may be applied to the cutting tool, and EMG signals may be read from sensors placed in muscles or other tissue innervated by the nerves of concern. By comparing the electrical signal applied to the cutting tool with the signals from the sensors, the patient monitoring system may determine the distance between the cutting tool and a nerve. Moreover, certain systems may disable power to the cutting tool based on the determined distance.
However, enabling and disabling power to a cutting tool may adversely affect the quality and accuracy of the resection or drilling being performed, especially if the cutting tool continuously toggles between an enabled and disabled state. Moreover, it may be difficult to determine an acceptable threshold distance for disabling power to the cutting tool.
The presently disclosed systems and methods for neural monitor-based dynamic haptics are directed to overcoming one or more of the problems set forth above and/or other problems in the art.